Power Control for Simultaneous Transmission of ACK/NACK and Channel-State Information in Carrier Aggregation Systems

ABSTRACT

Channel-state information and hybrid-ARQ ACK/NACK information for multiple carriers are simultaneously transmitted using a PUCCH Format 3 structure, where the hybrid-ARQ ACK/NACK bits and CSI bits are separately encoded and interleaved. In an example method, a power control offset parameter is calculated ( 2110 ) as a linear combination of at least a number N, representing a number of channel-state information bits and a number M, representing a number of hybrid-ARQ ACK/NACK bits. The method continues with the calculating ( 2120 ) of a power level for a transmission on a physical uplink control channel (PUCCH), using the power control offset parameter. In some embodiments, encoded channel-state information and hybrid-ARQ ACK/NACK bits are then transmitted ( 2060 ) according to the calculated power level. In some embodiments, the linear combination is of the form aN+bM+c, where a, b, and c are non-zero constants.

RELATED APPLICATION

This application claims the benefit of and priority to U.S. ProvisionalApplication Ser. No. 61/677,645, filed 31 Jul. 2012. The entire contentsof said U.S. Provisional Application are incorporated herein byreference

TECHNICAL FIELD

The present application is generally related to power control oftransmissions in wireless communications systems and is morespecifically related to power control as applied to the transmission ofAutomatic Repeat Request (ARQ) bits and channel-state information (CSI)bits in systems employing carrier aggregation techniques.

BACKGROUND

Carrier aggregation is one of the new features recently developed by themembers of the 3rd-Generation Partnership Project (3GPP) for so-calledLong Term Evolution (LTE) systems, and is standardized as part of LTERelease 10, which is also known as LTE-Advanced. An earlier version ofthe LTE standards, LTE Release 8, supports bandwidths up to 20 MHz.However, the very high data rates contemplated for LTE-Advanced willrequire an expansion of the transmission bandwidth. Accordingly,bandwidths up to 100 MHz are supported in LTE-Advanced. In order tomaintain backward compatibility with LTE Release 8 mobile terminals, theavailable spectrum is divided into Release 8-compatible chunks calledcomponent carriers. Carrier aggregation enables bandwidth expansionbeyond the limits of LTE Release 8 systems by allowing mobile terminalsto transmit and receive data over multiple component carriers, whichtogether can cover up to 100 MHz of spectrum. Importantly, the carrieraggregation approach ensures compatibility with earlier Release 8 mobileterminals, while also ensuring efficient use of a wide carrier by makingit possible for legacy mobile terminals to be scheduled in all parts ofthe wideband LTE-Advanced carrier.

The number of aggregated component carriers, as well as the bandwidth ofthe individual component carrier, may be different for uplink (UL) anddownlink (DL) transmissions. A carrier configuration is referred to as“symmetric” when the number of component carriers in each of thedownlink and the uplink are the same. In an asymmetric configuration, onthe other hand, the number of component carriers differs between thedownlink and uplink. Further, the number of component carriersconfigured for a geographic cell area may be different from the numberof component carriers seen by a given mobile terminal. A mobileterminal, for example, may support more downlink component carriers thanuplink component carriers, even though the same number of uplink anddownlink component carriers may be offered by the network in aparticular area.

LTE systems can operate in either Frequency-Division Duplex (FDD) modeor Time-Division Duplex (TDD) mode. In FDD mode, downlink and uplinktransmissions take place in different, sufficiently separated, frequencybands. In TDD mode, on the other hand, downlink and uplink transmissiontake place in different, non-overlapping time slots. Thus, TDD canoperate in unpaired spectrum, whereas FDD requires paired spectrum. TDDmode also allows for different asymmetries in terms of the amount ofresources allocated for uplink and downlink transmission, respectively,by means of different downlink/uplink configurations. These differingconfigurations permit the shared frequency resources to be allocated todownlink and uplink use in differing proportions. Accordingly, uplinkand downlink resources can be allocated asymmetrically for a given TDDcarrier.

One consideration for carrier aggregation is how to transmit controlsignaling from the mobile terminal on the uplink to the wirelessnetwork. Uplink control signaling may include acknowledgement (ACK) andnegative-acknowledgement (NACK) signaling for hybrid automatic repeatrequest (Hybrid ARQ, or HARQ) protocols, channel state information (CSI)and channel quality information (CQI) reporting for downlink scheduling,and scheduling requests (SRs) indicating that the mobile terminal needsuplink resources for uplink data transmissions. In LTE systems that usecarrier aggregation, a single uplink carrier is used by a mobileterminal to carry ACK/NACK and channel-state information for severaldownlink carriers. Further, in LTE systems that use TDD, ACK/NACKinformation for several downlink subframes may need to be transmitted ina single uplink subframe. In systems that use both TDD and carrieraggregation, a relatively large number of ACK/NACK bits and CSI bits mayneed to be transmitted in a single uplink subframe, on a single uplinkcarrier. Accordingly, improved techniques are needed for managing thetransmission of uplink control-channel information in systems thatemploy carrier aggregation and/or TDD.

SUMMARY

Channel-state information and hybrid-ARQ ACK/NACK information formultiple carriers may be simultaneously transmitted, using a PUCCHFormat 3 structure. Embodiments of the techniques disclosed hereininclude methods for simultaneous reporting of channel-state informationbits and hybrid-ARQ ACK/NACK bits for multiple downlink subframes ormultiple downlink carriers, or both. An example method begins withcalculating a power control offset parameter as a linear combination ofat least a number N, representing a number of channel-state informationbits and a number M, representing a number of hybrid-ARQ ACK/NACK bits.The method continues with the calculating of a power level for atransmission on a physical uplink control channel (PUCCH), using thepower control offset parameter.

In some embodiments, encoded channel-state information and hybrid-ARQACK/NACK bits are then transmitted according to the calculated powerlevel. In some embodiments, the linear combination is of the formaN+bM+c, where a, b, and c are non-zero constants.

In some of these and in other embodiments, the method further includesthe calculating of a power headroom parameter, based on the calculatedpower level and based on a calculated power level for shared channeltransmission. The power headroom parameter may then be transmitted to abase station.

Several of the methods summarized above may be implemented usingelectronic data processing circuitry provided in a mobile terminal. Eachmobile terminal, of course, also includes suitable radio circuitry forreceiving and transmitting radio signals formatted in accordance withknown formats and protocols, e.g., LTE formats and protocols.Accordingly, mobile terminal apparatus adapted to carry out any of thesetechniques are described in detail in the discussion that follows.

Of course, the disclosed techniques are not limited to theabove-summarized features and advantages. Indeed, those skilled in theart will recognize additional features and advantages upon reading thefollowing detailed description, and upon viewing the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a mobile communication system.

FIG. 2 illustrates a grid of time-frequency resources for a mobilecommunication system that uses OFDM.

FIG. 3 illustrates the time-domain structure of an LTE signal.

FIG. 4 illustrates the positioning of PUCCH resources in an uplinksubframe according to Release 8 standards for LTE.

FIG. 5 illustrates the mapping of ACK/NACK bits to uplink subframes in aTDD frame.

FIG. 6 illustrates the encoding and modulation of channel-statusinformation according to PUCCH Format 2.

FIG. 7 illustrates the aggregation of several carriers to form anaggregated bandwidth of 100 MHz.

FIG. 8 illustrates the encoding and modulation of multiple ACK/NACK bitsaccording to PUCCH Format 3.

FIG. 9 illustrates details of PUCCH Format 3 encoding and multiplexingfor up to 11 bits.

FIG. 10 illustrates details of PUCCH Format 3 encoding and multiplexingfor 12-21 bits.

FIG. 11 illustrates joint encoding of ACK/NACK bits and CSI bits.

FIG. 12 illustrates separate encoding of ACK/NACK bits and CSI bits.

FIGS. 13-18 are graphs illustrating the derivation of parameters for usein calculating a power control parameter.

FIG. 19 is a process flow diagram describing joint reporting of CSI andhybrid-ARQ ACK/NACK bits.

FIG. 20 illustrates a UE procedure to set the output power of a PUCCHformat 3 transmission.

FIG. 21 is a process flow diagram illustrating an example method forsimultaneous reporting of channel-state information bits and hybrid-ARQACK/NACK bits for multiple downlink subframes or multiple downlinkcarriers, or both.

FIG. 22 is a block diagram illustrating components of an examplecommunications node.

FIG. 23 illustrates functional components of an example mobile terminal.

DETAILED DESCRIPTION

In the discussion that follows, specific details of particularembodiments of the presently disclosed techniques are set forth forpurposes of explanation and not limitation. It will be appreciated bythose skilled in the art that other embodiments may be employed apartfrom these specific details. Furthermore, in some instances detaileddescriptions of well-known methods, nodes, interfaces, circuits, anddevices are omitted so as not obscure the description with unnecessarydetail. Those skilled in the art will appreciate that the functionsdescribed may be implemented in one or in several nodes. Some or all ofthe functions described may be implemented using hardware circuitry,such as analog and/or discrete logic gates interconnected to perform aspecialized function, ASICs, PLAs, etc. Likewise, some or all of thefunctions may be implemented using software programs and data inconjunction with one or more digital microprocessors or general purposecomputers. Where nodes that communicate using the air interface aredescribed, it will be appreciated that those nodes also have suitableradio communications circuitry. Moreover, the technology canadditionally be considered to be embodied entirely within any form ofcomputer-readable memory, including non-transitory embodiments such assolid-state memory, magnetic disk, or optical disk containing anappropriate set of computer instructions that would cause a processor tocarry out the techniques described herein.

Hardware implementations may include or encompass, without limitation,digital signal processor (DSP) hardware, a reduced instruction setprocessor, hardware (e.g., digital or analog) circuitry including butnot limited to application specific integrated circuit(s) (ASIC) and/orfield programmable gate array(s) (FPGA(s)), and (where appropriate)state machines capable of performing such functions.

In terms of computer implementation, a computer is generally understoodto comprise one or more processors or one or more controllers, and theterms computer, processor, and controller may be employedinterchangeably. When provided by a computer, processor, or controller,the functions may be provided by a single dedicated computer orprocessor or controller, by a single shared computer or processor orcontroller, or by a plurality of individual computers or processors orcontrollers, some of which may be shared or distributed. Moreover, theterm “processor” or “controller” also refers to other hardware capableof performing such functions and/or executing software, such as theexample hardware recited above.

Referring now to the drawings, FIG. 1 illustrates an exemplary mobilecommunication network 10 for providing wireless communication servicesto mobile terminals 100. Three mobile terminals 100, which are referredto as “user equipment” or “UE” in LTE terminology, are shown in FIG. 1.The mobile terminals 100 may comprise, for example, cellular telephones,personal digital assistants, smart phones, laptop computers, handheldcomputers, or other devices with wireless communication capabilities. Itshould be noted that the term “mobile terminal,” as used herein, refersto a terminal operating in a mobile communication network and does notnecessarily imply that the terminal itself is mobile or moveable. Thus,the term may refer to terminals that are installed in fixedconfigurations, such as in certain machine-to-machine applications, aswell as to portable devices, devices installed in motor vehicles, etc.

The mobile communication network 10 comprises a plurality of geographiccell areas or sectors 12. Each geographic cell area or sector 12 isserved by a base station 20, which is referred to in LTE as a NodeB orEvolved NodeB (eNodeB). One base station 20 may provide service inmultiple geographic cell areas or sectors 12. The mobile terminals 100receive signals from base station 20 on one or more downlink (DL)channels, and transmit signals to the base station 20 on one or moreuplink (UL) channels.

For illustrative purposes, several embodiments will be described in thecontext of a Long-Term Evolution (LTE) system. Those skilled in the artwill appreciate, however, that several embodiments of the disclosedtechniques may be more generally applicable to other wirelesscommunication systems, including, for example, WiMax (IEEE 802.16)systems.

LTE uses Orthogonal Frequency Division Multiplexing (OFDM) in thedownlink and Discrete Fourier Transform (DFT)-spread OFDM in the uplink.The basic LTE downlink physical resource can be viewed as atime-frequency grid. FIG. 2 illustrates a portion of the availablespectrum of an exemplary OFDM time-frequency grid 50 for LTE. Generallyspeaking, the time-frequency grid 50 is divided into one millisecondsubframes. Each subframe includes a number of OFDM symbols. For a normalcyclic prefix (CP) length, suitable for use in situations wheremultipath dispersion is not expected to be extremely severe, a subframeconsists of fourteen OFDM symbols. A subframe has only twelve OFDMsymbols if an extended cyclic prefix is used. In the frequency domain,the physical resources are divided into adjacent subcarriers with aspacing of 15 kHz. The number of subcarriers varies according to theallocated system bandwidth. The smallest element of the time-frequencygrid 50 is a resource element. A resource element consists of one OFDMsubcarrier during one OFDM symbol interval.

Resource elements are grouped into resource blocks, where each resourceblock in turn consists of twelve OFDM subcarriers, within one of twoequal-length slots of a subframe. FIG. 2 illustrates a resource blockpair, comprising a total of 168 resource elements.

Downlink transmissions are dynamically scheduled, in that in eachsubframe the base station transmits control information identifying themobile terminals to which data is transmitted and the resource blocks inwhich that data is transmitted, for the current downlink subframe. Thiscontrol signaling is typically transmitted in a control region, whichoccupies the first one, two, three, or four OFDM symbols in eachsubframe. A downlink system with a control region of three OFDM symbolsis illustrated in FIG. 2. The dynamic scheduling information iscommunicated to the UEs (“user equipment,” 3GPP terminology for a mobilestation) via a Physical Downlink Control Channel (PDCCH) transmitted inthe control region. After successful decoding of a PDCCH, the UEperforms reception of traffic data from the Physical Downlink SharedChannel (PDSCH) or transmission of traffic data on the Physical UplinkShared Channel (PUSCH), according to pre-determined timing specified inthe LTE specifications.

As shown in FIG. 3, LTE downlink transmissions are further organizedinto radio frames of 10 milliseconds, in the time domain, each radioframe consisting of ten subframes. Each subframe can further be dividedinto two slots of 0.5 milliseconds duration. Furthermore, resourceallocations in LTE are often described in terms of resource blocks,where a resource block corresponds to one slot (0.5 ms) in the timedomain and twelve contiguous subcarriers in the frequency domain.Resource blocks are numbered in the frequency domain, starting with 0from one end of the system bandwidth.

For error control, LTE uses hybrid-ARQ (HARQ), where, after receivingdownlink data in a subframe, the mobile terminal attempts to decode itand reports to the base station whether the decoding was successful(ACK) or not (NACK) via a Physical Uplink Control Channel (PUCCH). Inthe event of an unsuccessful decoding attempt, the base station (evolvedNodeB, or eNodeB, in 3GPP terminology) can retransmit the erroneousdata. Similarly, the base station can indicate to the UE whether thedecoding of the PUSCH was successful (ACK) or not (NACK) via thePhysical Hybrid ARQ Indicator CHannel (PHICH).

In addition to the hybrid-ARQ ACK/NACK information transmitted from themobile terminal to the base station, uplink control signaling from themobile terminal to the base station also includes reports related to thedownlink channel conditions, referred to generally as channel-stateinformation (CSI) or channel-quality information (CQI). This CSI/CQI isused by the base station to assist in downlink resource schedulingdecisions. Because LTE systems rely on dynamic scheduling of bothdownlink and uplink resources, uplink control-channel information alsoincludes scheduling requests, which the mobile terminal sends toindicate that it needs uplink traffic-channel resources for uplink datatransmissions.

In scenarios without downlink carrier aggregation, when a UE has data totransmit on PUSCH, it multiplexes the uplink control information withdata on PUSCH. Thus, a UE only uses PUCCH for signaling this uplinkcontrol information when it does not have any data to transmit on PUSCH.Accordingly, if the mobile terminal has not been assigned an uplinkresource for data transmission, Layer 1/Layer 2 (L1/L2) controlinformation, including channel-status reports, hybrid-ARQacknowledgments, and scheduling requests, is transmitted in uplinkresources (resource blocks) specifically assigned for uplink L1/L2control on the Physical Uplink Control CHannel (PUCCH), which was firstdefined in Release 8 of the 3GPP specifications (LTE Rel-8).

As illustrated in FIG. 4, these resources are located at the edges ofthe uplink cell bandwidth that is available to the mobile terminal foruse. Each physical control channel resource is made up of a pair ofresource blocks, where each resource block in turn consists of twelveOFDM subcarriers, within one of the two slots of the uplink subframe. Inorder to provide frequency diversity, the physical control channelresources are frequency hopped on the slot boundary—thus, the firstresource block of the pair is at the lower part of the spectrum withinthe first slot of the subframe while the second resource block of thepair is positioned at the upper part of the spectrum during the secondslot of the subframe (or vice-versa). If more resources are needed forthe uplink L1/L2 control signaling, such as in case of very largeoverall transmission bandwidth supporting a large number of users,additional resource blocks can be assigned, adjacent to the previouslyassigned resource blocks.

The reasons for locating the PUCCH resources at the edges of the overallavailable spectrum are two-fold. First, together with the frequencyhopping described above, this maximizes the frequency diversityexperienced by the control signaling, which can be encoded so that it isspread across both resource blocks. Second, assigning uplink resourcesfor the PUCCH at other positions within the spectrum, i.e., not at theedges, would fragment the uplink spectrum, making it difficult to assignvery wide transmission bandwidths to a single mobile terminal whilestill retaining the single-carrier property of the uplink transmission.

In LTE systems using TDD, hybrid-ARQ ACK/NACK feedback carried by asingle uplink subframe may correspond to several downlink subframes. Thetimings for HARQ A/N feedbacks for the PDSCH are specified withextensive tables and procedure descriptions for each U/D configurationsin the 3GPP specification, “Physical Channels and Modulation,” 3GPP TS36.211, v. 10.50.0 (June 2012), available at www.3gpp.org. According tothe Release 8 specifications of LTE, the UE shall feed back ACK/NACKinformation corresponding to decoded PDSCH transmissions in pre-defineduplink subframes. The UE shall transmit such hybrid-ARQ ACK/NACKresponse on the PUCCH in uplink subframe n if there is a PDSCHtransmission indicated by the detection of a corresponding PDCCH or ifthere is PDCCH indicating downlink SPS release within subframe(s) n−k,where k is within an association set K={k₀, k₁, . . . , k_(M-1)}, listedin Table 1.

The size of the association set K is denoted by M. The parameter M isused in the following to determine the PUCCH resources and signaling.The parameter M may take on different values in different subframes andin cells having different UL/downlink configurations. Note that, sincethe UL/downlink configurations of the aggregated cells must be identicalin Rel-10 TDD carrier aggregation, the parameters M for a subframe areidentical across all configured serving cells for a UE.

TABLE 1 Downlink association set index K = {k₀, k₁, . . . , k_(M−1)} forTDD UL-DL Subframe n Configuration 0 1 2 3 4 5 6 7 8 9 0 6 4 6 4 1 7, 64 7, 6 4 2 8, 7, 4, 6 8, 7, 4, 6 3 7, 6, 11 6, 5 5, 4 4 12, 8, 7, 11 6,5, 4, 7 5 13, 12, 9, 8, 7, 5, 4, 11, 6 6 7 7 5 7 7

Examples to illustrate the timing relationships specified in Table 1 areillustrated in FIG. 5. For uplink subframe 7 in a configuration 1 cell,Table 1 provides the association set K={7, 6}, which corresponds tocarrying possible HARQ A/N feedbacks for PDSCHs transmitted in subframes7−7=0 and 7−6=1. In FIG. 5, this is illustrated as arrows from downlinksubframes 0 and 1 to the uplink subframe 7, in the portion of the figurelabeled “Configuration #1.” The parameter M=2 for this downlink subframe7 in the configuration 1 cell.

Similarly, for uplink subframe 2 in the configuration 2 cell, Table 1provides the association set K={8, 7, 4, 6}, which corresponds tocarrying possible HARQ A/N feedbacks for PDSCHs transmitted in subframes4, 5, 6, and 8 of the preceding frame. This is illustrated as arrowsfrom these downlink subframes to the uplink subframe 2 in FIG. 5,Configuration #2. The parameter M=4 for this uplink subframe 2 in theconfiguration 2 cell.

Further, the number of subframes scheduled by the eNodeB can beindicated to the UE by utilizing 2 bits in the DCI format that indicatethe so called Downlink assignment index. The 2 bits represent the valuesaccording to Table 2. The DAI is used by the UE to detect whether it hasmissed a downlink assignment, for example.

TABLE 2 Downlink assignment Index Number of subframes with PDSCHtransmission and with DAI V_(DAI) ^(UL) or PDCCH indicating downlink SPSMSB, LSB V_(DAI) ^(DL) release 0, 0 1 1 or 5 or 9 0, 1 2 2 or 6 1, 0 3 3or 7 1, 1 4 0 or 4 or 8

When a UE has ACK/NACK to send in response to a downlink PDSCHtransmission, it determines which PUCCH resource to use from the PDCCHtransmission that assigned the PDSCH resources to the UE. Morespecifically, an index to the PUCCH resource for the UE is derived fromthe number of the first control channel element used to transmit thedownlink resource assignment. When a UE has a scheduling request or CQIto send, it uses a specific PUCCH resource that has been pre-configuredfor the UE by higher layer signaling.

Depending on the different types of information that PUCCH is to carry,several different PUCCH formats may be used. The data-carrying capacityof a pair of resource blocks during one subframe is more than isgenerally needed for the short-term control signaling needs of onemobile terminal. Therefore, to efficiently exploit the resources setaside for control signaling, multiple mobile terminals can share thesame physical control channel resource. This is done by assigning eachof several mobile terminals different orthogonal phase-rotations of acell-specific, length-12, frequency-domain sequence and/or differentorthogonal time-domain cover codes. By applying these frequency-domainrotations and/or time-domain covering codes to the encoded controlchannel data, as many as 36 mobile terminals can share a given physicalcontrol channel resource in some circumstances.

Several different encoding formats have been developed by 3GPP to encodedifferent quantities and types of uplink control channel data, withinthe constraints of a single physical control channel resource. Theseseveral formats, known generally as PUCCH Format 1, PUCCH Format 2, andPUCCH Format 3, are described in detail at pages 226-242 of the text “4GLTE/LTE-Advanced for Mobile Broadband,” by Erik Dahlman, StefanParkvall, and Johan Sköld (Academic Press, Oxford UK, 2011), and aresummarized briefly below.

PUCCH formats 1, 1a, and 1b, which are used to transmit schedulingrequests and/or ACK/NACK, are based on cyclic shifts of a Zadoff-Chusequence. A modulated data symbol is multiplied with the cyclicallyZadoff-Chu shifted sequence. The cyclic shift varies from one symbol toanother and from one slot to the next. Although twelve different shiftsare available, higher-layer signaling may configure UEs in a given cellto use fewer than all of the shifts, to maintain orthogonality betweenPUCCH transmissions in cells that exhibit high frequency selectivity.After the modulated data symbol is multiplied with the Zadoff-Chusequence, the result is spread using an orthogonal spreading sequence.PUCCH formats 1, 1a, and 1b carry three reference symbols per slot (whennormal cyclic prefix is used), at SC-FDMA symbol numbers 2, 3, and 4.

PUCCH Formats 1a and 1b refer to PUCCH transmissions that carry eitherone or two hybrid-ARQ acknowledgements, respectively. A PUCCH Format 1transmission (carrying only a SR) is transmitted on a UE-specificphysical control channel resource (defined by a particulartime-frequency resource, a cyclic-shift, and an orthogonal spreadingcode) that has been pre-configured by RRC signaling. Likewise, PUCCHFormat 1a or 1b transmissions carrying only hybrid-ARQ acknowledgementsare transmitted on a different UE-specific physical control channelresource. PUCCH Format 1a or 1b transmissions that are intended to carryboth ACK/NACK information and a scheduling request are transmitted onthe assigned SR resource for positive SR transmission, and are encodedwith the ACK/NACK information.

PUCCH Format 1/1a/1b transmissions carry only one or two bits ofinformation (plus scheduling requests, depending on the physical controlchannel resource used for the transmission). Because channel-stateinformation reports require more than two bits of data per subframe,PUCCH Format 2/2a/2b is used for these transmissions. As illustrated inFIG. 6, in PUCCH formats 2, 2a, and 2b, the channel-status reports arefirst block-coded, and then the block-coded bits for transmission arescrambled and QPSK modulated. (FIG. 6 illustrates coding for a subframeusing a normal cyclic prefix, with seven symbols per slot. Slots usingextended cyclic prefix have only one reference-signal symbol per slot,instead of two.) The resulting ten QPSK symbols are then multiplied witha cyclically shifted Zadoff-Chu type sequence, a length-12 phase-rotatedsequence, where again the cyclic shift varies between symbols and slots.Five of the symbols are processed and transmitted in the first slot,i.e., the slot appearing on the left-hand side of FIG. 6, while theremaining five symbols are transmitted in the second slot. PUCCH formats2, 2a, and 2b carry two reference symbols per slot, located on SC-FDMAsymbol numbers 1 and 5.

For UEs operating in accordance with LTE Release 8 or LTE Release 9(i.e., without carrier aggregation), it is possible to configure the UEin a mode where it reports ACK/NACK bits and CSI bits simultaneously. Ifthe UE is using normal cyclic prefix, one or two ACK/NACK bits aremodulated onto a QPSK symbol on the second reference signal (RS)resource element in each slot of the PUCCH format 2. If one ACK/NACK bitis modulated on the second RS in each slot, the PUCCH format used by theUE is referred to as PUCCH Format 2a. If two ACK/NACK bits are modulatedon the second RS in each slot the PUCCH format used by the UE isreferred to as PUCCH Format 2b. If the UE is configured with extendedcyclic prefix, one or two ACK/NACK bits are jointly coded withchannel-state information (CSI) feedback and transmitted together withinPUCCH format 2.

As with PUCCH Format 1 transmissions, a pair of resource blocksallocated to PUCCH can carry multiple PUCCH Format 2 transmissions fromseveral UEs, with the separate transmissions separated by the cyclicshifting. As with PUCCH Format 1, each unique PUCCH Format 2 resourcecan be represented by an index from which the phase rotation and otherquantities necessary are derived. The PUCCH format 2 resources aresemi-statically configured. It should be noted that a pair of resourceblocks can either be configured to support a mix of PUCCH formats2/2a/2b and 1/1a/1b, or to support formats 2/2a/2b exclusively.

3GPP's Release 10 of the LTE standards (LTE Release 10) has beenpublished and provides support for bandwidths larger than 20 MHz,through the use of carrier aggregation. One important requirement placedon the development of LTE Release 10 specifications was to assurebackwards compatibility with LTE Release 8. The need for spectrumcompatibility dictated that an LTE Release 10 carrier that is wider than20 MHz should appear as a number of distinct, smaller bandwidth, LTEcarriers to an LTE Release 8 mobile terminal. Each of these distinctcarriers can be referred to as a component carrier.

For early LTE Release 10 system deployments in particular, it can beexpected that there will be a relatively small number of LTE Release10-capable mobile terminals, compared to many “legacy” mobile terminalsthat conform to earlier releases of the LTE specifications. Therefore,it is necessary to ensure the efficient use of wide carriers for legacymobile terminals as well as Release 10 mobile terminals, i.e., that itis possible to implement carriers where legacy mobile terminals can bescheduled in all parts of the wideband LTE Release 10 carrier.

One straightforward way to obtain this is by means of a technique calledcarrier aggregation. With carrier aggregation, an LTE Release 10 mobileterminal can receive multiple component carriers, where each componentcarrier has (or at least may have) the same structure as a Release 8carrier. The basic concept of carrier aggregation is illustrated in FIG.7, which illustrates the aggregation of five 20-MHz component carriersto yield an aggregated bandwidth of 100 MHz. Release 10 of the LTEstandards specifies support of up to five aggregated carriers, whereeach carrier is limited to one of six radio-frequency (RF) bandwidths,namely 1.4, 3, 5, 10, 15, and 20 MHz.

The number of aggregated component carriers as well as the bandwidth foreach individual component carrier may be different for uplink anddownlink. In a symmetric configuration, the number of component carriersin downlink and uplink is the same, whereas the numbers of uplink anddownlink carriers differ in an asymmetric configuration.

During initial access, an LTE Release 10 mobile terminal behavessimilarly to an LTE Release 8 mobile terminal, requesting and obtainingaccess to a single carrier for the uplink and downlink. Upon successfulconnection to the network a mobile terminal may—depending on its owncapabilities and the network—be configured with additional componentcarriers in the uplink (UL) and downlink (DL).

Even if a mobile terminal is configured with additional componentcarriers, it need not necessarily monitor all of them, all of the time.This is because LTE Release 10 supports activation of componentcarriers, as distinct from configuration. The mobile terminal monitorsfor PDCCH and PDSCH only component carriers that are both configured andactivated. Since activation is based on Medium Access Control (MAC)control elements—which are faster than RRC signaling—theactivation/de-activation process can dynamically follow the number ofcomponent carriers that is required to fulfill the current data rateneeds. All but one component carrier—the downlink Primary componentcarrier (downlink PCC)—can be deactivated at any given time.

When carrier aggregation is used in LTE, one uplink carrier is designedto carry the HARQ-ACK/NACK bits for all downlink-carrier PDSCHtransmissions. To enable the possibility to transmit more than four bitsof A/N, PUCCH Format 3 can be used. In FDD scenarios, each downlinkcarrier can generate one or two HARQ ACK/NACK bits per scheduledsubframe, depending on whether multiple-input multiple-output (MIMO)operation is enabled for that carrier. In TDD scenarios, the number ofHARQ ACK/NACK bits also depends on how many downlink subframes a givenuplink subframe should carry HARQ ACK/NACK bits for.

PUCCH Format 3, which is designed for scenarios when more than four bitsof information must be transmitted, is based on Discrete FourierTransform (DFT)-spread OFDM. FIG. 8 shows a block diagram of thatdesign, for one of the two slots of an LTE subframe. The same processingis applied to the second slot of the uplink frame. In the illustratedscenario, multiple ACK/NACK bits (which may be combined with a singlescheduling request (SR) bit) are encoded, using a Reed-Muller (RM)forward-error correction (FEC) code, to form 48 coded bits. (Some of the32 output-coded bits produced by the RM encoder are repeated to producethe 48 coded bits.) The coded bits are then scrambled, usingcell-specific (and possibly DFT-spread OFDM symbol dependent) sequences.24 bits are transmitted within the first slot and the other 24 bits aretransmitted within the second slot. The 24 bits per slot are then mappedinto 12 QPSK symbols, as indicated by the blocks labeled “QPSK mapping”in FIG. 8, which appear in five of the OFDM symbols of the slot (symbols0, 2, 3, 4, and 6). The sequence of symbols in each of these fivesymbols in the slot is spread with OFDM-symbol-specific orthogonal covercodes, indicated by OC0, OC1, OC2, OC3, and OC4 in FIG. 8, andcyclically shifted, prior to DFT-precoding. The DFT-precoded symbols areconverted to OFDM symbols (using an Inverse Fast-Fourier Transform, orIFFT) and transmitted within one resource block (the bandwidth resource)and five DFT-spread OFDM symbols (the time resource). The spreadingsequence or orthogonal cover code (OC) is UE-specific and enablesmultiplexing of up to five users within the same resource blocks.

For the reference signals (RS), cyclic-shifted constant-amplitudezero-autocorrelation (CAZAC) sequences can be used. For example, thecomputer optimized sequences in 3GPP TS 36.211, “Physical Channels andModulation,” can be used. To improve orthogonality among referencesignals even further, an orthogonal cover code of length two could beapplied to the reference signals. However, this approach is not used inReleases 10 or 11 of the LTE specifications.

If the number of ACK/NACK bits exceeds eleven, then the bits are splitinto two parts and two RM encoders are used, one for each of the twoparts. This is known as the dual-RM code. Up to twenty ACK/NACK bits(plus one SR bit) can be supported by PUCCH Format 3 in this manner.Each encoder in the dual-RM code outputs twenty-four bits which areconverted to twelve QPSK symbols, and the resulting two sets of twelveQPSK symbols are distributed across the slots and interleaved over thesubcarriers so that the twelve symbols from the first encoder are mappedto odd subcarriers and the twelve symbols from the second encoder aremapped to even subcarriers, where six odd and six even sub-carriers areassumed per slot. (In this mapping operation, a cell-, slot-, andsymbol-specific cyclic shift of the symbols in the time domain isincluded, to provide inter-cell interference randomization.) The twelveQPSK symbols per slot are then spread across the five DFTS-OFDM symbols,using one out of five orthogonal cover codes, as in the single-RM codecase.

Some details of the encoding and multiplexing approach described aboveare shown in FIGS. 9 and 10. FIG. 9 illustrates the approach for up toeleven uplink control information (UCI) bits. As described above, inthis case the UCI bits are encoded to produce 48 bits, using a singleencoder. These 48 bits are mapped to 24 QPSK symbols, which are dividedbetween the first and second slots of the uplink subframe carrying thePUCCH. FIG. 10, on the other hand, illustrates the approach taken for 12to 21 UCI bits. In this case, the UCI bits are split into two segments,which are supplied to two separate encoders. Each encoder produces 24encoded bits, which are mapped into twelve QPSK symbols. The 12 QPSKsymbols from each encoder are distributed, on an interleaved basis,between the two slots of the uplink subframe.

The operation of the multiplexing scheme illustrated in FIG. 9 isdescribed by the following algorithm, in which {tilde over (b)}₀, {tildeover (b)}₁, {tilde over (b)}₂, . . . , {tilde over (b)}₂₃ is the outputsequence from the first encoder and {tilde over ({tilde over (b)}₀,{tilde over ({tilde over (b)}₁, {tilde over ({tilde over (b)}₂, . . . ,{tilde over ({tilde over (b)}₂₃ the output sequence from the secondencoder. N_(sc) ^(RB)=12 is the number of subcarriers per resourceblock. The output bit sequence b₀, b₁, b₂, . . . , b_(B-1), whereB=4·N_(sc) ^(RB), is obtained by the alternate concatenation of the bitsequences {tilde over (b)}₀, {tilde over (b)}₁, {tilde over (b)}₂, . . ., {tilde over (b)}₂₃ and {tilde over ({tilde over (b)}₀, {tilde over({tilde over (b)}₁, {tilde over ({tilde over (b)}₂, . . . , {tilde over({tilde over (b)}₂₃ as shown in the following pseudo-code:

Set i, j = 0 while i < 4 · N_(sc) ^(RB)   b_(i) = {tilde over (b)}_(j) ,b_(i+1) = {tilde over (b)}_(j+1)   b_(i+2) = 

 , b_(i+3) = 

  i = i + 4   j = j + 2 end while.

For Release 11 of the LTE specifications, it has been decided to use thePUCCH Format 3 structure for feedback of the CSI and multi-cell (i.e.,multi-carrier) ACK/NACK plus SR. One possible approach for encoding theCSI and ACK/NACK bits is to use a joint encoding approach, in which theCSI, ACK/NACK, and SR bits are concatenated before a single or dual-RMencoder. If the total payload is larger than 11 bits, the dual RMencoder is used, similar to the ACK/NACK case in the Release 10 use ofPUCCH Format 3. FIG. 11 illustrates an example for each of thesetechniques for joint encoding. The top portion of FIG. 11 shows anexample approach to encoding of up to 11 payload bits, using a single RMencoder, while the bottom portion illustrates an example approach toencoding between 12 and 22 bits, using a dual RM encoder. In both cases,ACK/NACK bits and CSI bits are jointly encoded.

Another approach under consideration, separate encoding, also uses adual RM encoder, but the CSI bits are encoded by one encoder and theACK/NACK bits are encoded by another. When a SR bit is present, it canbe encoded together with the ACK/NACK bits. One key advantage of theseparate encoding approach, as described in more detail below, is thatit can provide different levels of error protection to the CSI andACK/NACK bits, avoiding over-protection of the ACK/NACK bits and energywaste.

With this approach, the code rates applied to the CSI bits and ACK/NACKbits, respectively, can be adjusted by a parameter Δ, which is referredto herein as an “encoding-imbalance parameter” or a “rate-matchingparameter.” The significance of this encoding-imbalance parameter Δ canbe seen in the scenario illustrated in FIG. 12. There it can be seenthat the ACK/NACK bits (plus the SR bit, if present) are encoded by afirst RM encoder, which produces 24+Δbits. The CSI bits are encoded aseparate RM encoder, which in turn produces 24-Δbits. Thus, the twoencoders together produce 48 bits, regardless of the value of Δ; these48 bits can then easily be scrambled, modulated, and mapped to the PUCCHFormat 3 structure for transmission to the base station.

In general, then, the encoding-imbalance parameter Δ adjusts the numberof output encoded bits from the two encoders while keeping the totalnumber of coded bits unchanged. In some embodiments, the parameter Δ isrestricted to even integer value. With this approach, every two codedbits at the output of each encoder can be easily mapped to a single QPSKsymbol.

Referring once again to FIG. 12, it will be appreciated that if Δ isincreased, then RM encoder 1 lowers the code rate while RM encoder 2increases the code rate, such that the total number of encoded bitsremains constant. Hence, an increased Δ gives better channel codingprotection for the bits encoded by RM encoder 1, while reducingprotection for the bits encoded by RM encoder 2. Hence, the level ofprotection for the two payloads can be adjusted, which is useful if thetwo payloads are different and/or if they have different errorrequirements. Note that Δ can be a positive as well as a negative eveninteger. For a positive Δ, more protection is provided to the HARQ A/Nand SR bits, relative to the CSI bits, given the configurationillustrated in FIG. 12. For a negative Δ, more protection is provided tothe CSI bits. Each codeword can have the same error protection, i.e.,Δ=0, or unequal error protection with Δ≠0.

Scheduling of a component carrier is done using the PDCCH or ePDCCH(extended PDCCH), via downlink assignments. Control information on thePDCCH or ePDCCH is formatted as a Downlink Control Information (DCI)message. In Release 8, where a mobile terminal only operates with onedownlink and one uplink component carrier, the association betweendownlink assignment, uplink grants, and the corresponding downlink anduplink component carriers is very clear. In Release 10, however, twomodes of carrier aggregation need to be distinguished. The first mode isvery similar to the operation of multiple Release 8 mobile terminals, inthat a downlink assignment or uplink grant contained in a DCI messagetransmitted on a component carrier applies either to the downlinkcomponent carrier itself or to a uniquely associated uplink componentcarrier. (This association may be either via cell-specific orUE-specific linking.) A second mode of operation augments a DCI messagewith a Carrier Indicator Field (CIF). A DCI containing a downlinkassignment with CIF applies to the specific downlink component carrierindicated by the CIF, while a DCI containing an uplink grant with CIFapplies to the indicated uplink component carrier.

DCI messages for downlink assignments contain, among other things,resource block assignment, modulation and coding scheme relatedparameters, and HARQ redundancy version indicators. In addition to thoseparameters that relate to the actual downlink transmission, most DCIformats for downlink assignments also contain a bit field for TransmitPower Control (TPC) commands. These TPC commands are used to control theuplink power control behavior of the corresponding PUCCH that is used totransmit the HARQ feedback.

Each downlink assignment is scheduled with its own DCI message on thePDCCH. Because Release 8 DCI formats, or formats very similar to Release8, are used also for Release 10, each received DCI message contains aTPC bit field that contains an adjustment value for the transmit powerfor PUCCH. Since all TPC commands address the same uplink componentcarrier and/or PUCCH, it has been proposed to only transmit the true TPCcommand in one TPC field, and reuse TPC fields in other DCI messages fornon-power control related information. Doing this enables higher daterates for non-redundant control information.

The Release 10 specifications for LTE specify the power to be used fortransmitting PUCCH as follows:

${P_{PUCCH}(i)} = {\min {\begin{Bmatrix}{{P_{{CMAX},c}(i)},} \\\begin{matrix}{P_{0{\_ PUCCH}} + {PL}_{c} + {h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} +} \\{{\Delta_{F\_ PUCCH}(F)} + {\Delta_{T \times D}\left( F^{\prime} \right)} + {g(i)}}\end{matrix}\end{Bmatrix}.}}$

The parameters in this formula are given in Table 3. Note that thisexpression includes an accumulated power adjustment value g(i), which isderived from the TPC commands δ_(PUCCH)(i) sent by the eNodeB to the UE.

TABLE 3 Power control parameters P_(PUCCH) (i) PUCCH transmit power forsubframe i P_(CMAX) Configured maximum transmit power for PUCCH CC, e.g.uplink PCC P₀_PUCCH Desired PUCCH receive power signaled by higherlayers h(n_(CQI), n_(HARQ)) Offset parameter that depends on numbern_(CQI) of CQI bits or number n_(HARQ) of HARQ bits, to retain the sameenergy per information bit. Δ_(F)_PUCCH (F) Offset parameter thatdepends on PUCCH format, to give sufficient room for different receiverimplementation and radio conditions Δ_(TxD) (F′) Is set determined ifthe UE is configured with two antenna ports or a single antenna port. Ifthe UE is configured with a single antenna port the parametercorresponds to 0.${g(i)} = {{g(i)} + {\sum\limits_{m = 0}^{M - 1}\; {\delta_{PUCCH}\left( {i - k_{m}} \right)}}}$Accumulated power adjustment value derived from TPC command δ_(PUCCH)(i). The values M and k_(m) are depending if the duplexing mode is FDDor TDD. PL Pathloss

Generally speaking, the baseline operating point for all PUCCH formatsis common, i.e., PUCCH formats 1/1a/1b/2/2a/2b/3 and channel selectionall use the same power control loop, with the exception of two powercontrol parameters h(n_(CQI),n_(HARQ)) and Δ_(F) _(—) _(PUCCH)(F). Theseparameters take into account different performance and payload sizes forthe different PUCCH formats. Therefore, these parameters areindividually determined per PUCCH format.

In the discussion that follows, the term n_(HARQ) generally refers to anumber of ACK/NACK bits. However, an SR bit, when transmitted can betaken into account in the same manner as ACK/NACK. Thus, n_(HARQ) canalso be understood to refer to the number of ACK/NACK bits+SR bit.Furthermore, while n_(CQI) denotes the number of channel-stateinformation (CSI) bits, it should be understood that channel-stateinformation bits can include channel quality indicator (CQI) and/or rankindicator (RI) and/or pre-coding matrix indicator (PMI) bits.

In the event that PUCCH is transmitted together with PUSCH, a powerheadroom report (PHR) is defined as:

${{PH}_{{type}\; 2}(i)} = {{P_{{CMAX},c}(i)} - {10 \log_{10}{\quad{\begin{pmatrix}{10^{{({{10\; {\log_{10}{({M_{{PUSCH},c}{(i)}})}}} + {P_{{O\_ PUSCH},c}{(j)}} + {{\alpha_{c}{(j)}} \cdot {PL}_{c}} + {\Delta_{{TF},c}{(i)}} + {f_{c}{(i)}}})}/10} +} \\10^{(\begin{matrix}{P_{0{\_ {PUCCH}}} + {PL}_{c} + {h{({n_{CQI},n_{HARQ},n_{SR}})}} + {\Delta_{F\_ PUCCH}{(F)}} +} \\{{{{\Delta_{T \times D}{(F^{\prime})}} + {g{(i)}}})}/10}\end{matrix})}\end{pmatrix},}}}}$

where the power control parameters are defined as above and as in 3GPP36.213, “Physical Layer Procedures,” v. 10.4.0 (November 2011),available at www.3gpp.org.

In the Release 10 specifications for LTE, the power control term isdefined as follows:

-   -   For PUCCH format 1,1a and 1b, h(n_(CQI), n_(HARQ), n_(SR))=0.    -   For PUCCH format 1b with channel selection, if the UE is        configured with more than one serving cell,

${{h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = \frac{\left( {n_{HARQ} - 1} \right)}{2}},{otherwise},{{h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = 0.}$

-   -   For PUCCH format 2, 2a, 2b and normal cyclic prefix,

${h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = \left\{ \begin{matrix}{10{\log_{10}\left( \frac{n_{CQI}}{4} \right)}} & {{{if}\mspace{14mu} n_{CQI}} \geq 4} \\0 & {otherwise}\end{matrix} \right.$

-   -   For PUCCH format 2 and extended cyclic prefix

${h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = \left\{ \begin{matrix}{10{\log_{10}\left( \frac{n_{CQI} + n_{HARQ}}{4} \right)}} & {{{{if}\mspace{14mu} n_{CQI}} + n_{HARQ}} \geq 4} \\0 & {otherwise}\end{matrix} \right.$

-   -   For PUCCH format 3:        -   If the UE is configured by higher layers to transmit PUCCH            on two antenna ports, or if the UE transmits more than 11            bits of HARQ-ACK/SR,

${{h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = \frac{n_{HARQ} + n_{SR} - 1}{3}},{Otherwise}$${h\left( {n_{CQI},n_{HARQ},n_{SR}} \right)} = {\frac{n_{HARQ} + n_{SR} - 1}{2}.}$

For carrier-aggregation PUCCH format 3 there is a need to have adefinition of h(n_(CQI),n_(HARQ)) that applies when the UE is configuredby higher layers to transmit HARQ-ACK/SR and CSI bits simultaneously.This problem is addressed herein by determining an expression forh(n_(CQI),n_(HARQ)) that is applicable to PUCCH format 3 under thesecircumstances.

As detailed further below, the best h(n_(CQI),n_(HARQ)) to use for thesecircumstances is a linear function of n_(HARQ) and n_(CQI) given by:

h(n _(CQI) ,n _(HARQ))=an _(HARQ) +bn _(CQI) +c,

where a, b and c are constant values. A UE configured according to thetechniques described herein applies the corresponding calculatedh(n_(CQI),n_(HARQ)) when setting the transmission power for PUCCH format3 transmission. Likewise, a UE configured according to these techniquesapplies the power control term h(n_(CQI),n_(HARQ)) calculated accordingto this approach when computing PHR.

As discussed above, h(n_(CQI),n_(HARQ)) as defined in 3GPP's Release 10specifications depends on the number of HARQ-ACK, SR and CSI bits to betransmitted, while the signal-to-noise ratio (SNR) offset due todifferent radio channels, receiver implementation and PUCCH format istaken care by Δ_(F) _(—) _(PUCCH)(F).

To determine h(n_(CQI),n_(HARQ)) and Δ_(F) _(—) _(PUCCH)(F), we make theassumption that the eNodeB can correctly control the power of PUCCHformat 1a. With that assumption, one approach to obtainh(n_(CQI),n_(HARQ)) is to fit a curve that matches the slope of alldifferent scenarios corresponding to different channel type, velocity,receiver algorithms, bandwidth, etc. These curves can be used todetermine Δ_(F) _(—) _(PUCCH)(F), in the same process, by calculatingthe difference between PUCCH format 1a and the corresponding PUCCHformat 3 curves for each scenario.

The following explains in more detail how to evaluate the slopes ofh(n_(CQI),n_(HARQ)) for each variable, i.e., a orb for n_(HARQ) andn_(CQI), respectively.

Based on extensive evaluations, it has been observed that the powercontrol for PUCCH format 3 transmission of joint CSI, HARQ bits and SRis best based on a linear combination of the number of HARQ-ACK, SR andCSI bits according to below:

h(n _(CQI) ,n _(HARQ))=an _(HARQ) +bn _(CQI) +c.  (1)

In this equation, the variable n_(HARQ) represents the number ofHARQ-bits and scheduling request indication. In other words, thescheduling request bit, i.e., SR bit, and the HARQ bits are consideredtogether in the variable n_(HARQ). Of course, another possible notationis to have a separate variable for SR n_(SR) and a separate notation forn_(HARQ). For the remainder of this discussion, it should be consideredthat in every occasion where an n_(HARQ) is written, it can be replacedby n_(HARQ)+n_(SR).

The number of hybrid-ARQ ACK/NACK bits that are accounted for inn_(HARQ) can, for example, be one of the following definitions:

-   -   (1) the number of transport blocks that are possible to schedule        within the HARQ-ACK feedback window;    -   (2) the number of transport blocks and downlink SPS releases        that have been received by the UE within the HARQ-ACK feedback        window;    -   (3) the number of combined HARQ-ACK bits that the UE reports        back, based on the configured number of transport blocks per        component carrier it aggregates; or    -   (4) a number of combined HARQ-ACK bits that UE transmits that        does not correspond to transport block that was not received by        the UE. In this case, if the UE performs spatial bundling        between two processes, where one process corresponds to a        received transport block and the other process corresponds to a        process which did not receive a transport block, it is counted        as a single combined HARQ-ACK bit.

In example number 2 above, n_(HARQ) can be described for FDD as:

${n_{HARQ} = {\sum\limits_{c = 0}^{N_{cells}^{DL} - 1}N_{c}^{received}}},$

where N_(cells) ^(DL) is the number of configured cells and N_(c)^(received) is the number of transport blocks or the SPS release PDCCH,if any, received in subframe in serving cell.

Example number 2 can also be described as the following, for a TDDsystem:

${n_{HARQ} = {\sum\limits_{c = 0}^{N_{cells}^{DL} - 1}{\sum\limits_{k \in K}N_{k,c}^{received}}}},$

where N_(k,c) ^(received) is the number of transport blocks or the SPSrelease PDCCH, if any, received in subframe n−k in serving cell c, wherekεK, and M is the number of elements in K defined in Table 1.

Example 4 can further be described, for example, as:

${n_{HARQ} = {\sum\limits_{c = 0}^{N_{cells}^{DL} - 1}\left( {{\left( {\left( {V_{{DAI},c}^{DL} - U_{{DAI},c}} \right){mod}\; 4} \right) \cdot n_{c}^{ACK}} + {\sum\limits_{k \in K}N_{k,c}^{received}}} \right)}},$

where V_(DAI,c) ^(DL) is the V_(DAI) ^(DL) in serving cell c, U_(DAI,c)is the U_(DAI) in serving cell c, and n_(c) ^(ACK) is the number ofHARQ-ACK bits corresponding to the configured downlink transmission modeon serving cell c. In the event that spatial HARQ-ACK bundling isapplied, n_(c) ^(ACK)=1 and N_(k,c) ^(received) is the number of PDCCHor PDSCH without a corresponding PDCCH received in subframe n−k andserving cell c, where kεK and M is the number of elements in K. In theevent that spatial HARQ-ACK bundling is not applied, N_(k,c) ^(received)is the number of transport blocks received or the SPS release PDCCHreceived in subframe n−k in serving cell c, where kεK and M is thenumber of elements in K in Table 1. V_(DAI,c) ^(DL)=0 if no transportblock or SPS release PDCCH is detected in subframe(s) n−k in servingcell c, where kεK. It is further given that U_(DAI) represent the totalnumber of PDCCH(s) with assigned PDSCH transmission(s) and PDCCHindicating downlink SPS release detected by the UE within thesubframe(s) n−k in serving cell c, where kεK. Further, V_(DAI) ^(DL) isthe value of the DAI in PDCCH with DCI format detected by the UE,according to Table, in subframe n−k_(m) in serving cell c, where k_(m)is the smallest value in the set K according to Table 1, such that theUE detects a DCI format.

Furthermore, the scheduling request bit can indicate either 1 or 0 inaccording to the following possibilities:

-   -   (1) Indicate 1 if subframe i is configured for SR for the UE not        having any associated transport block for UL-SCH, otherwise=0.    -   (2) Indicate 1 if the UE has positive scheduling request for        subframe i not having any associated transport block for UL-SCH,        otherwise=0.

In equation (1), n_(CQI) represents the number of CSI bits, which can,for example, be the number of PMI, CQI, RI and/or PTI bits. The numberof bits can be based on the number of information bits that are reportedat the specific occasion. Alternatively, it can be based on a wantednumber of report information bits at the specific occasion.

It is further observed that it is possible to re-write equation (1) toeliminate the constant c, so that the effects of the constant c areincluded in the term Δ_(F) _(—) _(PUCCH) (F). Consequently equation (1)can alternatively be expressed as follows:

h(n _(CQI) ,n _(HARQ))=an _(HARQ) +bn _(CQI).  (2)

As shown above, the power control function can be represented accordingto either equation (1) or equation (2). To determine a, i.e., the slopecorresponding to the number of HARQ-ACK bits and SR bit, the offset dueto different scenarios such as the number of CSI bits and/or propagationchannel types and/or bandwidths and/or receiver algorithms should betaken away from the corresponding operating SNR values for variousnumber of HARQ-ACK bits and SR bit. Then, a slope which best fits theresultant relative SNR curves versus number of HARQ-ACK bits and SR bitshould be used to determine the slope a.

The same procedure as above can be applied to determine the slope b,which corresponds to the number of CSI bits, n_(CQI). However, in thiscase, the offset due to different scenarios such as number of HARQ-ACKbits and SR bit and/or propagation channel types and/or bandwidthsand/or receiver algorithms should be taken away from the correspondingoperating SNR values for various number of CSI bits. Then, a slope whichbest fits the resultant relative SNR curves versus number of CSI bitsshould be used to determine the slope b.

Other constraints on h(n_(CQI),n_(HARQ)) may be imposed, such as toinclude a constant value in the h(n_(CQI),n_(HARQ)) expression, which iscaptured by c. For example, to be consistent with LTE power controlspecifications, h(n_(CQI),n_(HARQ)) should be such thath(n_(CQI)=0,n_(HARQ)=1)=0. This parameter could be included inh(n_(CQI),n_(HARQ)) or can be captured by Δ_(F) _(—) _(PUCCH)(F).

To illustrate the procedure explained above for PUCCH format 3 forsimultaneous transmission of HARQ-ACK or/and SR and CSI, consider thefollowing. As mentioned earlier, two main candidates, referred to asjoint and separate coding, are proposed for encoding CSI and hybrid-ARQACK/NACK bits (and SR). FIGS. 13 and 14 demonstrate the operating SNR indB versus the number of ACK/NACK bits for several different channeltypes (including the Extended Typical Urban (ETU) and ExtendedPedestrian A (EPA) models) and UE velocities, as well as for differentnumbers of CSI bits. FIG. 13 illustrates the curves for joint encoding,while FIG. 14 shows the corresponding curves for separate encoding ofthe CSI and ACK/NACK bits. In both cases, the operating SNR for format1a is given as well.

FIGS. 15 and 16 show how the operating SNR curves correspondingrespectively to FIGS. 13 and 14 are moved to find a slope with best fitwhen the number of HARQ-ACK bits and SR bit is varying, thus yieldrelative operating SNR curves. Similar methodology is applied todetermine the best slope when the number of CSI bits is varying, asshown in FIGS. 17 and 18 for joint and separate coding respectively.

As a result, the best fit is found to be a=1/2 and b=1/3. Moreover,c=−1/2 fulfills the requirement h(n_(CQI)=0,n_(HARQ)=1)=0, which couldalternatively be captured by Δ_(F) _(—) _(PUCCH)(F).

This means that for simultaneous transmission of HARQ-ACK, SR and CSIbits, irrespective of the encoding scheme, the best expression forh(n_(CQI),n_(HARQ)) is given by

${h\left( {n_{CQI},n_{HARQ}} \right)} = {\frac{n_{HARQ} - 1}{2} + {\frac{n_{CQI}}{3}.}}$

Hence, it is given that Δ_(F) _(—) _(PUCCH)(F)=0 or alternatively can beΔ_(F) _(—) _(PUCCH)(F)=0.5. Other values for Δ_(F) _(—) _(PUCCH)(F) arealso possible, considering implementation margin for UE and eNB.

In FIGS. 13 to 18, the number of A/N bits represents the number ofHARQ-ACK bits and/or SR bit.

In several embodiments, the UE will apply the correspondingh(n_(CQI),n_(HARQ)) and Δ_(F) _(—) _(PUCCH)(F) described above insetting the UEs transmission power. In some of these and in some otherembodiments, the UE will apply the corresponding h(n_(CQI),n_(HARQ)) andΔ_(F) _(—) _(PUCCH)(F) described above when determining a power headroomreport including a PUCCH report.

Likewise, in some embodiments an eNodeB power controls the PUCCH of a UEassuming that the UE will adapts its transmission power according to oneof the formulations described above. In some of these and in some otherembodiments, the eNodeB receives a PHR calculated based on theformulations discussed above. In a further sub-embodiment, the eNodeButilizes the PHR report for uplink scheduling, for example for linkadaption of PUSCH, SRS and/or PUCCH transmissions.

FIG. 19 is a signal flow diagram illustrating joint reporting of CSI andhybrid-ARQ ACK/NACK bits at the system level, i.e., between a UE andeNodeB. As shown at 1910, the signaling flow begins with the eNodeBconfiguring the UE for periodic CSI reporting. Subsequently, as shown at1920, the eNodeB schedules downlink transmissions, and transmits thedownlink assignments to the UE. At each periodic CSI reporting occasion,the UE simultaneously transmits CSI bits and ACK/NACK bits (plus an SRbit). One of these occasions is shown at 1930.

FIG. 20 illustrates a UE procedure to set the output power of a PUCCHformat 3 transmission according to embodiments of the presentlydisclosed techniques. As seen at block 2010, the UE receives one or moredownlink assignments. (Note that this corresponds to the signaling shownat 1920 in FIG. 19.) Based on the downlink assignments, the UE can countthe number of received transport blocks, as shown at block 2020. Thisdetermines the number of HAR ACK/NACK bits, as shown at block 2030. TheUE also determines a number of CSI bits that need to be transmitted, asshown at block 2040. Then, as shown at block 2050, the UE determines andsets a transmission power of a PUCCH format 3 transmission, based on thepayload of CSI and ACK/NACK bits. Finally, the UE transmits PUCCH format3, carrying encoded CSI and ACK/NACK bits, as shown at block 2050.

The process flow diagram in FIG. 21 illustrates details of how the powerlevel for the PUCCH format 3 is carried out. It will be appreciated,then, that the process illustrated in FIG. 21 may be a subset of theoperations carried out in the operation illustrated at block 2050 ofFIG. 20.

Referring to FIG. 21, the illustrated process begins, as shown at block2110, with calculating a power control offset parameter as a linearcombination of at least a number N, representing a number ofchannel-state information bits and a number M, representing a number ofhybrid-ARQ ACK/NACK bits. Next, as shown at block 2120, the UEcalculates a power level for a transmission on a physical uplink controlchannel (PUCCH), using the power control offset parameter. As wasillustrated at block 2060 of FIG. 20, the UE may then transmit encodedchannel-state information and hybrid-ARQ ACK/NACK bits according to thecalculated power level.

In some embodiments of the process illustrated in FIG. 21, the linearcombination referred to above is of the form aN+bM+c, where a, b, and care non-zero constants. In some of these and in some other embodiments,the number M may represent the number of hybrid-ARQ ACK/NACK bits and ascheduling request (SR) bit.

In some embodiments, the process continues with the calculation of apower headroom parameter based on the calculated power level and basedon a calculated power level for shared channel transmission. The powerheadroom parameter may then be transmitted to a base station. Theseoperations are shown at block 2130 and 2140 of FIG. 21. Note, however,that these blocks are represented with a dashed outline, indicating thatthese operations are “optional,” in the sense that they may not appearin every embodiment or in every scenario.

The functions in the block diagrams and process flow diagrams discussedabove may be implemented using electronic data processing circuitryprovided in the mobile terminal and in a base station. Each mobileterminal and base station, of course, also includes suitable radiocircuitry for receiving and transmitting radio signals formatted inaccordance with known formats and protocols, e.g., LTE formats andprotocols.

FIG. 22 illustrates features of an example communications node 2200embodying the techniques described above. Although the detailedconfiguration, as well as features such as physical size, powerrequirements, etc., will vary, the general characteristics of theelements of communications node 2200 are common to both a wireless basestation and a mobile terminal. Further, both may be adapted to carry outone or several of the techniques described above for encoding andtransmitting ACK/NACK bits and channel-state information or decodingsuch information from a received signal.

Communications node 2200 comprises a transceiver 2220 for communicatingwith mobile terminals (in the case of a base station) or with one ormore base stations (in the case of a mobile terminal) as well as aprocessing circuit 2210 for processing the signals transmitted andreceived by the transceiver 2220. Transceiver 2220 includes atransmitter 2225 coupled to one or more transmit antennas 2228 andreceiver 2230 coupled to one or more receive antennas 2233. The sameantenna(s) 2228 and 2233 may be used for both transmission andreception. Receiver 2230 and transmitter 2225 use known radio processingand signal processing components and techniques, typically according toa particular telecommunications standard such as the 3GPP standards forLTE and/or LTE-Advanced. Because the various details and engineeringtradeoffs associated with the design and implementation of suchcircuitry are well known and are unnecessary to a full understanding ofthe techniques described herein, additional details are not shown here.

Processing circuit 2210 comprises one or more processors 2240, hardware,firmware or a combination thereof, coupled to one or more memory devices2250 that make up a data storage memory 2255 and a program storagememory 2260. Memory 2250 may comprise one or several types of memorysuch as read-only memory (ROM), random-access memory, cache memory,flash memory devices, optical storage devices, etc. Again, because thevarious details and engineering tradeoffs associated with the design ofbaseband processing circuitry for mobile devices and wireless basestations are well known and are unnecessary to a full understanding ofthe techniques described herein, additional details are not shown here.

Typical functions of the processing circuit 2210 include modulation andcoding of transmitted signals and the demodulation and decoding ofreceived signals. In several embodiments, processing circuit 2210 isadapted, using suitable program code stored in program storage memory2260, for example, to carry out one of the techniques described abovefor encoding and transmitting ACK/NACK bits and channel-stateinformation or decoding such information from a received signal. Moreparticularly, the processing circuit in some embodiments is adapted tocalculate a power control offset parameter as a linear combination of atleast a number N, representing a number of channel-state informationbits and a number M, representing a number of hybrid-ARQ ACK/NACK bits,and to calculate a power level for a transmission on a physical uplinkcontrol channel (PUCCH), using the power control offset parameter. Insome embodiments, the processing circuit 2210 is further adapted tocalculate a power headroom parameter based on the calculated power leveland based on a calculated power level for shared channel transmission.The power headroom parameter may then be transmitted to a base station.Of course, it will be appreciated that not all of the steps of thesetechniques are necessarily performed in a single microprocessor or evenin a single module.

FIG. 23 illustrates several functional elements of a mobile terminal2300, adapted to carry out some of the techniques discussed in detailabove. Mobile terminal 2300 includes a processing circuit 2310configured to receive data from a base station, via receiver circuit2315, and to construct a series of uplink subframes for transmission bytransmitter circuit 2320. In several embodiments, processing circuit2310, which may be constructed in the manner described for theprocessing circuits 2210 of FIG. 23, includes a hybrid-ARQ processingunit 2340, which is adapted to determine that first channel-stateinformation (from channel-state measurement unit 2350) and firsthybrid-ARQ ACK/NACK bits corresponding to a plurality of downlinksubframes or a plurality of downlink carriers, or both, are scheduledfor transmission in an uplink subframe. Processing circuit 2310 furtherincludes an uplink control channel encoding unit 2330. This unit, whichmay be at least partly configured according to the block diagram of FIG.8, for example, is adapted to encode the hybrid-ARQ ACK/NACK bits andthe channel-state information, using joint or separate encoders, tointerleave the encoded hybrid-ARQ ACK/NACK bits and the encodedchannel-state information bits, and to send both the first channel-stateinformation and the first hybrid-ARQ ACK/NACK bits in physical controlchannel resources of the first uplink subframe, on a single carrier. Ofcourse, all of the variants of the techniques described above areequally applicable to mobile terminal 2300 as well.

It will be appreciated by the person of skill in the art that variousmodifications may be made to the above described embodiments withoutdeparting from the scope of the presently described techniques. Forexample, it will be readily appreciated that although the aboveembodiments are described with reference to parts of a 3GPP network,other embodiments will also be applicable to like networks, such as asuccessor of the 3GPP network, having like functional components.Therefore, in particular, the terms 3GPP and associated or related termsused in the above description and in the enclosed drawings and anyappended claims now or in the future are to be interpreted accordingly.

Examples of several embodiments have been described in detail above,with reference to the attached illustrations of specific embodiments.Because it is not possible, of course, to describe every conceivablecombination of components or techniques, those skilled in the art willappreciate that the techniques described above can be implemented inother ways than those specifically set forth herein, without departingfrom essential characteristics of the techniques. The presentembodiments are thus to be considered in all respects as illustrativeand not restrictive.

1-12. (canceled)
 13. A method in a mobile terminal configured forsimultaneous reporting of channel-state information bits and hybrid-ARQACK/NACK bits for multiple downlink subframes or multiple downlinkcarriers, or both, the method comprising, for each of a first pluralityof reporting instances: calculating a power control offset parameter asa linear combination of at least a number N, representing a number ofchannel-state information bits, and a number M, representing a number ofhybrid-ARQ ACK/NACK bits; and calculating a power level for atransmission on a physical uplink control channel (PUCCH), using thepower control offset parameter.
 14. The method of claim 13, furthercomprising, for each of the plurality of reporting instances,transmitting encoded channel-state information and hybrid-ARQ ACK/NACKbits according to the calculated power level.
 15. The method of claim13, wherein said linear combination is of the form aN+bM+c, where a, b,and c are non-zero constants.
 16. The method of claim 13, furthercomprising calculating a power headroom parameter based on thecalculated power level and based on a calculated power level for sharedchannel transmission.
 17. The method of claim 16, further comprisingtransmitting the power headroom parameter to a base station.
 18. Themethod of claim 13, wherein the number M represents the number ofhybrid-ARQ ACK/NACK bits and a scheduling request (SR) bit.
 19. A mobileterminal configured to simultaneously report channel-state informationbits and hybrid-ARQ ACK/NACK bits for multiple downlink subframes ormultiple downlink carriers, or both, the mobile terminal comprising areceiver circuit, a transmitter circuit, and a processing circuit,wherein the processing circuit is adapted to, for each of firstplurality of reporting instances: calculate a power control offsetparameter as a linear combination of at least a number N, representing anumber of channel-state information bits, and a number M, representing anumber of hybrid-ARQ ACK/NACK bits; and calculate a power level for atransmission on a physical uplink control channel (PUCCH), using thepower control offset parameter.
 20. The mobile terminal of claim 19,wherein the processing circuit is further adapted to, for each of theplurality of reporting instances, control the transmitter circuit totransmit the encoded channel-state information and hybrid-ARQ ACK/NACKbits according to the calculated power level.
 21. The mobile terminal ofclaim 19, wherein said linear combination is of the form aN+bM+c, wherea, b, and c are non-zero constants.
 22. The mobile terminal of claim 19,wherein the processing circuit is further adapted to calculate a powerheadroom parameter based on the calculated power level and based on acalculated power level for shared channel transmission.
 23. The mobileterminal of claim 22, wherein the processing circuit is further adaptedto, for each of the plurality of reporting instances, control thetransmitter circuit to transmit the power headroom parameter to a basestation.
 24. The mobile terminal of claim 19, wherein the number Mrepresents the number of hybrid-ARQ ACK/NACK bits and a schedulingrequest (SR) bit.